<?php
	$px = isset($_GET['px']) ? $_GET['px'] : 0; $px = preg_replace('/[^0-9]/isU', '', $px);
	$py = isset($_GET['py']) ? $_GET['py'] : 0; $py = preg_replace('/[^0-9]/isU', '', $py);
	
	if ($px<1) $px = 5;
	if ($py<1) $py = 5;
	
	if ($px>20) $px = 20;
	if ($py>20) $py = 20;
	
	$width	= 100;
	$height	= 100;
	$im = imagecreatetruecolor($width, $height);
	
	for($y=0; $y<$height; $y+= $py)
	{
		for($x=0; $x<$width; $x+= $px)
		{
			$c = imagecolorallocate($im, 200-$x, 100+$y, 100+$x-$y);
			imagefilledrectangle($im, $x, $y, $x+$px, $y+$py, $c);
		}
	}
	
	header("Content-type: image/png");
	imagepng($im);
	imagedestroy($im);
?>